Detection of light source distortion in an imaging system

Abstract

An imaging system includes a plurality of optical sensors arranged on an integrated circuit in an array with a plurality of rows and a plurality of columns. The system includes an interface communicating with the plurality of optical sensors, memory storing operational instructions and processing circuitry configured to sample an image using the plurality of optical sensors in a first mode and sample at least a portion of the image sequentially on a row-by-row basis at a predetermined sampling rate in a second mode to produce row by row sample outputs. The processing circuitry is further configured to initiate sampling at least some rows of the plurality of rows of optical sensors using different time stamps.

What is claimed is: 
     
       1. An imaging system, comprising:
 a plurality of optical sensors on an integrated circuit, wherein the plurality of optical sensors are arranged in an array, wherein the array comprises a plurality of rows and a plurality of columns; 
 a plurality of sets of optical filters configured in a layer having a respective top surface and a respective bottom surface, wherein the bottom surface of the plurality of sets of optical filters is located proximal to the plurality of optical sensors, wherein each optical filter of a set of optical filters is configured to pass light in a different wavelength range; 
 an interface configured to interface and communicate with the plurality of optical sensors; 
 memory that stores operational instructions; 
 processing circuitry operably coupled to the interface and to the memory, wherein the processing circuitry is configured to execute the operational instructions to:
 sample an image in a first mode; and 
 sample at least a portion of the image sequentially on a row-by-row basis at a predetermined sampling rate in a second mode to produce row-by-row sample outputs, wherein the processing circuitry is further configured to initiate sampling at least some rows of the plurality of rows of optical sensors using different time stamps. 
 
 
     
     
       2. The imaging system of  claim 1 , wherein the processing circuitry is further configured to execute the operational instructions to determine, based on the row-by-row sample outputs, intensity variation associated with the image recurring at a substantially regular intervals. 
     
     
       3. The imaging system of  claim 2 , wherein the processing circuitry is further configured to execute the operational instructions to determine the intensity variation using a frequency-temporal algorithm. 
     
     
       4. The imaging system of  claim 3 , wherein the frequency-temporal algorithm is selected from a group consisting of:
 a Fast Fourier Transform (FFT); 
 a Discrete Fourier Transform (DFT); and 
 a 2D Fast Fourier Transform (2D-FFT). 
 
     
     
       5. The imaging system of  claim 1 , wherein a set of optical filters includes a plurality of optical filters arranged in spatial pattern, wherein the spatial pattern includes an area without an optical filter. 
     
     
       6. The imaging system of  claim 1 , wherein the row by row sample outputs indicate an intensity variation recurring at a substantially regular interval. 
     
     
       7. An imaging system, comprising:
 a first plurality of optical sensors, wherein the first plurality of optical sensors are arranged in an array; 
 a second plurality of optical sensors, wherein the second plurality of optical sensors are interspersed among the first plurality of optical sensors; 
 a processing module, wherein the processing module is configured to receive an output from each optical sensor of the first and second plurality of optical sensors, wherein the processing module is further configured to:
 sample a scene at a first frequency using the first plurality of optical sensors to produce a first image; 
 sample the scene over a period of time T at a second frequency using the second plurality of optical sensors to produce an intensity over T, wherein the second frequency is higher than the first frequency; and 
 determine, based on the intensity over T, light distortion associated with the scene. 
 
 
     
     
       8. The imaging system of  claim 7 , wherein the first plurality of optical sensors and the second plurality of optical sensors are located on a same integrated circuit. 
     
     
       9. The imaging system of  claim 7 , wherein the first plurality of optical sensors and the second plurality of optical sensors have a respective sensitivity to light, wherein the sensitivity to light of the second plurality of optical sensors is higher than the sensitivity to light of the first plurality of optical sensors. 
     
     
       10. The imaging system of  claim 7 , wherein the first frequency is between 80 and 120 Hz and the second frequency is between 250 and 650 Hz. 
     
     
       11. The imaging system of  claim 7 , further comprising:
 a plurality of sets of optical filters configured in a layer having a respective top surface and a respective bottom surface, wherein the bottom surface of the plurality of sets of optical filters is located proximal to the plurality of optical sensors, wherein each optical filter of a set of optical filters is configured to pass light in a different wavelength range, wherein one or more filters of the set of optical filters is adapted to pass light in a wavelength range specific to one or more optical sensors of the second plurality of optical sensors. 
 
     
     
       12. The imaging system of  claim 11 , wherein the processing module is further configured to sample the scene sequentially on a row-by-row basis to produce row-by-row sample outputs. 
     
     
       13. The imaging system of  claim 11 , wherein the processing module is further configured to sample the scene at a predetermined sampling rate. 
     
     
       14. The imaging system of  claim 11 , wherein the array comprises a plurality of rows and a plurality of columns of optical sensors, and wherein the processing module is further configured to initiate sampling at least some rows of the plurality of rows using a plurality of different time stamps. 
     
     
       15. The imaging system of  claim 7 , wherein each optical sensor of the second plurality of optical sensors is interleaved between a plurality of optical sensors of the first plurality of optical sensors. 
     
     
       16. The imaging system of  claim 15 , wherein the processing module is further configured to sample the first plurality of optical sensors sequentially using a first sequence and sample the second plurality of optical sensors sequentially using a second sequence. 
     
     
       17. The imaging system of  claim 11 , wherein one or more optical sensors of the second plurality of optical sensors is configured to have a larger dynamic range than any optical sensor of the first plurality of optical sensors. 
     
     
       18. A method for imaging a scene comprises:
 sampling the scene in a first mode using a digital imager, wherein the digital imager includes a plurality of optical sensors arranged in an array, wherein the array comprises a plurality of rows and a plurality of columns of optical sensors; 
 sampling at least a portion of the scene sequentially on a row-by-row basis at a predetermined sampling rate in a second mode to produce row-by-row sample outputs, wherein the sampling for at least some rows of the plurality of rows of optical sensors uses different time stamps; and 
 determining an intensity variation for the row-by-row sample outputs using a frequency-temporal algorithm. 
 
     
     
       19. The method of  claim 18 ,
 wherein the determining an intensity variation includes determining whether the intensity variation occurs at regular intervals. 
 
     
     
       20. The method of  claim 19 , wherein the digital imager is adapted to include another plurality of other optical sensors, wherein the sampling at least a portion of the scene sequentially on a row-by-row basis is executed using the other optical sensors. 
     
     
       21. The method of  claim 18 , wherein the second mode includes sampling photo-hole currents for at least some optical sensors of the plurality of optical sensors. 
     
     
       22. The method of  claim 21 , further comprising determining, based on the photo-hole currents, the intensity variation. 
     
     
       23. The method of  claim 21 , wherein the intensity variation is further based on a frequency-temporal algorithm. 
     
     
       24. The method of  claim 18 , further comprising: 
       sampling the at least a portion of the scene sequentially on a row-by-row basis at another predetermined sampling rate. 
     
     
       25. The method of  claim 18 , wherein the digital imager includes a plurality of sets of optical filters overlaying the plurality of optical sensors. 
     
     
       26. The method of  claim 18 , wherein each optical filter of a set of optical filters is configured to pass light in a different wavelength range.